Electric transformer



Nov. 17, 1931. J. B. BoRGADT .ELECTRIC TRANSFORMER 2' Sheets-Shea?.

Filed Jan. 8, 1931 NIW@ WF m NN m QH *H NN MN NN -INVENTORZ Lf. 5.30 7&0

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ATTORNEYS Nov. 17, 1931. .1. B. BORGADT ELECTRIC TRANSFORMER 2 Sheets-Shee Filed Jan. 8, 1951 ATTORNEYS Patented Nov. 17, 1931 JOHN B. BOBGADT, F EAST CLEVELAND, OHIO ELECTRIC TRANSFORMEB Substitute for application Serial No. 95,649,

The present invention relates in general to electric transformers, and more particularly to transformers of that type which are adapted for use in connection with electric welding machines, being designed to give a current of high amperage and low voltage. This application is a substitute for my application` Serial No. 95,649, filed March 18, 1926 and allowed January 26, 1929.

1o While the electric transformer of this application may be used in connection with any conventional form of electric weldmg machine, it is especially adapted for use in connection with the tube welding machine for which Patent No. 1,580,401 was granted to me on April 13, 1926.

Among the objects of the invention are to provide a secondary winding which 1s divided into a plurality of spaced sections,

the spacing between the sections permitting air cooling of the coil and being adapted to be varied to obtain a predetermined impedance.

A further object of the invention is to provide a novel means for supporting the secondary winding independently of the primary winding.

While one particular embodiment of the invention is shown and described'in detail in this application, it will be understood that many modifications and changes can be made in the details of construction without departino` from the spirit of the invention.

For a full understanding of the invention,

reference is to be had to the following d escription and accompanying drawings 1n which:

Fig. 1 is a side elevation of an electric transformer which is constructed in accord,-

ance with the invention Fig. 2 is an end view thereof; Fig. 3 is a horizontal sectional view on the line 3 3 of Fig. 1; Fig. 4 is a 'top plan view of one of the lower bracket members; Fig. 5 is a side elevation thereof;

Fig. 6 is a top plan viewof one of the up er bracket members; Fig. 7 is a side elevatlon thereof, one end of the bracket being broken away; Fig. 8 is an enlarged detail perspective view of one of the combined supporting and 50. insulating members for the outer edges of led March 18, 1926. This application illed January 8, 1831. Serial No. 507,513.

the secondary winding; and Fig. 9 is a similar view of one of the insulating and supporting members which are interposed between the l mgs and, as shown on the drawings, there are `four sections 3 of primary windings which are applied to the cross bar 1 and held rmly in place b v the frame.

Applied to the top of the core A at opposite, l

ends of the primary coils are the upper brackets 4. In a similar manner lower brackets 5 are applied to the bottom of the core at opposite ends of the primary winding. The upper and lower brackets are formed at end and intermediate portions thereof with corresponding eyes 6 which project laterally and receive tie bolts 7. These bolts engage the edges of the laminated core A to hold the said core in place and are tightened to hold the laminas together. The base portion of each of the upper and lower brackets 4 and 5 is also formed with an intermediate foot member 8 and end feet 9. These feet project laterally from the brackets and rest upon the laminated core A, the intermediate feet 8 entering the end sections 3 of the primary winding.

The secondary winding is formed in two units B. B, each of which comprises a single turn built u of thin flexible copper strips or laminse to t e required current carryin capacitv necessary for welding purposes. ach unit B of the secondary winding comprises a plurality of strips or sections which may be variably spaced to obtain a larger or a smaller internal reactance as may be desired for the particular work to be done. As shown on the drawings, each unit B comprisesl an inner strip 10, an intermediate strip 11, and an outer stri 12, said strips being spaced and gradually ecreasing in thickness from the mner strip to the outer strip. The spacing between the strips provides for air cooling of the winding, and in designing the transformer these spaces'can be made larger or smaller to obtain J. larger or a small internal reactance. The strips 10, 11 and 12 have a laminated formation, being built up to the required current carrying capacity from laminae which are usually .010 or .015 inch in thickness. Ordinarilyvno portion of the secondary is more than %ths of an inch in thickness, it being a known fact that alternating current of commercial frequencies does not penetrate beneath a surface stratum, so that any metal in a conductor above this thickness, whether laminated or solid, is useless.

The secondary winding which comprises the two units B, B is supported independently of the primary and is rigidly held in position to resist the thrusts to which it is subjected by the electromagnetic action of the transformer. insulating blocks 13, vone of which is shown by Figure 9, are interposed at suitable intervals between the units B, B,

while the outer edges of the units are engaged by insulating blocks 14, one of which is shown by Fig. 8. The insulating blocks 13 and 14 are formed in their faces with grooves 15 which receive edge portions of the strips 10, 11 and 12 of the respective units B Yof the secondary winding. The insulating blocks 14 are shown as formed in their outer faces with openings 16 which are adapted to receive positioning pins 17 projecting from arms 4a of the upper bracket 4 and arms 5 of the lower bracket 5. Corresponding arms of the upper and lower brackets are connected by cross bolts 18 which pass through openings in the ends of the arms and also pass through openings 19 in the intermediate insulating blocks 13. By tightening these bolts the upper brackets 4 and lower brackets 5 are drawn toward each other so that the sections or strips of the units B of the secondary winding are firmlv seated in the grooves 15 of the insulatino: blocks 13 and 14. The intermediate insulating blocks 13 are held in position by engagement with the cross bolts 18. while the outermost insulating blocks 14 are held firmly in proper position b v engagement with the positioning pins 17. The proper spacing between the sections 10, 11 and 12of the secondary winding is thus rigidly maintained and by substituting different insulating blocks the spacing between the sections or concentric strips of the secondary winding can be varied. This arrangementprovides the designer with greater flexibility and enables him to accurately predetermine the operating characteristics of the transformer. Thelower brackets 5 are alsoshown as formed with depending feet 5b which are of assistance in properly supporting the transformer in position when it is in use. A 5 The ends of the split or 4divided Secondary winding each terminate in two arms 20 between which a lead 21 is inserted. Each of the leads is clamped to the arms 20 at the respective end of the secondary winding by means of the bolts 22 and plates 23, whereby the large contact area necessary for carrying a heav welding current is obtained. The interme iate strip or division 11 of each unit of the secondary winding has the ends thereof divided and a portion thereof connected to one side of the arms thereof, while the other portion thereof is connected to the other side arm 20.

The invention provides a construction whereby the secondary windin is rigidly supported independently of t e primary winding and is in spaced relation thereto so that air can circulate between the same for .preventing overheating. winding is also divided into divisions or strips which are rigidly supported to resist the electromagnetic thrusts, and which may be variably spaced to obtain the desired impedance. This is an improvement over the ordinary transformer of this type in which the secondary is loosely built up of laminae without spacing or supports, and with this transformer the heavy currents necessary for electric Welding can be obtained.

What I claim is:

1. An electric transformer including a secondary winding which comprises a wide conductor strip, and insulator supports fitted against opposite edges thereof and formed with notches to receive the edges of the strip.

2. An electric transformer including a secondary winding comprising a plurality of wide conductor strips arranged in a side by side relation, brackets on opposite sides of the secondary winding, tie bolts connecting the brackets, and insulator supports engaging the edges of the wide conductor strips, certain of the insulator supports being carried by the brackets and others being mounted on the tie bolts.

v3. An electric transformer including a secondary winding which is divided longitudinally into a plurality of independent sections, and readily exchangeable means for rigidly supporting the sections in various predetermined spaced relations to obtain a desired impedance.

4. An electric transformer including a laminated secondary which is divided longitudinally into a plurality of sections, insulators engaging the sections, and means cooperating with the insulators to clamp the sections rigidly in a spaced relation.

5. A transformer including a secondary winding, brackets on opposite sides thereof, insulators carried by the brackets and engaging the secondary winding, and cross bolts connecting the brackets to maintain the insulators in operative engagement with the secondary winding.

The secondary 6. An electric transformer including a magnetic core, a primary winding thereon, brackets applied'to the magnetic core, t1e bolts connecting the brackets to clam them in osition on the core, a secondary wlnding, and) means for supporting4 the secondary winding in a spaced relation to the primary winding by means of other bolts connecting the brackets.

7. An electric transformer including a magnetic core, a primary winding thereon, brackets applied to opposite sides of the core, tie bolts connecting the brackets to clamp them against the core, a secondary winding, insulators engaging the secondary winding, and other bolts connectingy the brackets and serving to clamp the insulators in a rigid engagement with the secondary winding to support the same ina spaced relation to the primary winding.

8. An electric transformer including a magnetic core, a primary winding thereon, opposed brackets applied to the edges of the magnetic core on opposite sides thereof, tie bolts connecting the brackets to clamp them against the core, a secondary winding, cross bolts connecting the brackets and arranged at substantially right angles to the tie bolts, and means cooperating with the cross bolts to support the secondary winding in a spaced relation to the primary winding.

9. An electric transformer including a magnetic core, a primary winding thereon, corresponding brackets applied to opposite sides of the magnetic core and provided with lateral feet which lit against the magnetic core and extend within the primary winding, tie bolts connecting the brackets to clamp them against the magnetic core, a secondary winding, other bolts connecting the brackets, a-nd means cooperating with the other bolts to provide a rigid support for the secondary winding. y

10. An electric Vtransformer including a magnetic core, a primary Winding thereon,

brackets applied to opposite sides ofthe magnetic core, tie bolts connecting` the brackets to clamp them against the magnetic core, a secondary winding comprising a plurality 0f wide conductor'strips arranged in a side by side relation, intermediate supports interposed between the conductor strips and engaging the same, end supports interposed between the brackets and the conductor strips, and bolts connecting the brackets for holding the supports in operative engagement with the conductor strips.

11. An electric transformer including a q magnetic core, a primary winding thereon, brackets applied to opposite sides of the magnetic core, tie bolts connecting the brackets to clamp them against the magnetic core, a secondary winding including a plurality of wide conductor strips, intermediate insulator supports interposed between opposite edges of the conductor strip, and

means kfor holding the insulator supports firmly in operative position.

13. An electric transformer including a secondary winding which comprises a. 1urality of wide conductor strips arrange in a side by side relation, intermediate supports interposed between the conductor strips, and supports engaging the outer edges of the conductor strips, side brackets, and cross bolts connecting the side brackets and holding the insulator supports in operative engagement with the conductor strips ofthe secondary winding.

14. An ,electric transformer including a secondary winding which comprisesa lurality of wide conductor strips arrange in a side by side relation, each of the conductor strips being divided longitudinally into a plurality of spaced sections, and means for rigidly supporting the strips with the longitudinal divisions thereof 1n a spaced relation to each other.

15. An electric transformer including a secondary winding which comprises a wide conductor strip, said strip being divided longitudinallyinto a plurality of sections, insulator supports engaging the edges yof thel stripv and formed with notches to receive the divisions thereof,l and means for clamping the insulator supports against the conductor strip.

16. An electric transformer including a secondary winding which comprises a wide conductor strip, said strip being divided longitudinally `into a plurality of spaced sections arranged one within another and with their width towards the primary, and unitary means for rigidly supporting the strip with the longitudinal divisions thereof in spaced relation to each other.

In witness whereof, I hereby aiiix my signature. u

' JOHN B. BORGADT. 

